FIG. 1 is a view schematically showing a conventional backlight unit.
As shown in FIG. 1, the conventional backlight unit comprises an LED module 10, a case 20, a fixing part 30 and a reflective sheet 40.
The LED module 10 comprises a printed circuit board 11, an LED 13 formed on the printed circuit board 11, and a mold part 15 formed on the LED 13.
The reflective sheet 40 reflects light, which is emitted from the LED 13, in the upward direction. The reflective sheet 40 is formed with an opening for exposing the LED 13. The reflective sheet 40 has reflectivity of 98% or more.
The fixing part 30 fixes the reflective sheet 40 and the LED module 10 to the case 20. The case 20 may be a cover bottom. An upper portion of the fixing part 30 is exposed on the reflective sheet 40. For instance, the fixing part 30 comprises a screw. In general, the fixing part 30 has reflectivity of about 60 to 70%.
Since there is a difference in reflectivity between the reflective sheet 40 and the fixing part 30, the conventional backlight unit represents non-uniform brightness distribution as shown in FIG. 2. FIG. 2 is a view showing a problem of the conventional backlight unit.
An optical sheet 70, such as a diffusion sheet, can be aligned on the backlight unit. Since the fixing part 30 has relatively low reflectivity, brightness of a region where the fixing part 30 is positioned may be lowered relative to other regions. Thus, a dark line may occur in the region where the fixing part 30 is positioned, causing non-uniform brightness distribution.